code: def export_empty_string_split() -> None:
      node = onnx.helper.make_node(
          "StringSplit",
          inputs=["x"],
          outputs=["substrings", "length"],
          delimiter=None,
          maxsplit=None,
      )
  
      x = np.array([]).astype(object)
  
      substrings = np.array([]).astype(object).reshape(0, 0)
  
      length = np.array([], dtype=np.int64)
  
      expect(
          node,
          inputs=[x],
          outputs=[substrings, length],
          name="test_string_split_empty_tensor",
          output_type_protos=[
              onnx.helper.make_tensor_type_proto(
                  onnx.TensorProto.STRING, (0, None)
              ),
              None,
          ],
      )
  
file_path: onnx/onnx/backend/test/case/node/string_split.py
imports: import numpy
  import onnx
  from onnx.backend.test.case.base import Base
  from onnx.backend.test.case.node import expect
label_desc: Use image node_id 5 for calling the StringSplit obj's underlying member method code with example usage: obj.export_empty_string_split() without return types